Cannabis use and anticipatory pleasure as reported by subjects with early psychosis and community controls

Background: There is evidence of decreased pleasure and deficits in the anticipation of reward in both psychotic illness and drug addiction. Individuals with low anticipatory pleasure may preferentially engage in behaviours associated with immediate reward such as cannabis use.

Method: Ninety-one psychosis patients and 91 controls without history of psychosis were administered the Temporal Experience of Pleasure Scale (TEPS), a self report which measures anticipatory and consummatory pleasure. Cannabis use diagnosis was assessed using the Structured Clinical Interview for DSM IV (SCID). Subjects reported the frequency of cannabis consumption and time since last use.

Results: Patients did not show a significant deficit in anticipatory or consummatory pleasure compared to controls; however, patients with an active cannabis-use disorder tended to have lower consummatory pleasure than controls with active cannabis disorder (p<.05). Patients who continued to use cannabis during treatment of their first episode of psychosis reported significantly lower anticipatory pleasure compared to those who had a lifetime cannabis diagnosis but were able to maintain abstinence (F(1,60)=5.6, p=.021). Frequency of cannabis use was negatively correlated to anticipatory and consummatory pleasure (Pearson R=-.46, -.48 respectively) in 37 patients currently using cannabis but not in 46 cannabis-using controls (partial R=-.04, -.07 respectively).

Conclusion: Anticipatory pleasure may not be decreased in early psychosis patients. Lower hedonic response may be associated with persistent, heavy cannabis use in patients in the early phase of psychotic disorders.